What is use case?
Specific interaction or behaviour between users (called actors) and a system to achieve specific goals or complete a task.
What is an actor?
A role or entity interacts with system to achieve a particular goal or perform a specific action.
An actor can be people, other software systems, or hardware devices
What is a scenario ?
sequence of events that describe steps taken by actor and system to accomplish a specific task or achieve a goal
USE CASE ELEMENTS
Actors
Use Cases
Associations
System Boundary
Relationships
USE CASE PROPERTIES
Simplicity
Communication
Functional Requirements
Use Case Relationships
Scope Definition
Abstraction